<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <style>
        body{
            height:630px;
        }
        table,th,td{
            border:1px solid black;

        }
        table{
             border-collapse:collapse;
             width:100%;
             height:150px;
             text-align:center;
        }
        th{
            background-color:#F5F5DC
        }
        tr:hover{
             background-color:#808080
        }
        .head,#footer{
             text-align:center;
             padding=20px;
             background-color:#DAA520;
        }
        .head h1{
             text-align:center;
        }
        .middle{
             padding=20px;
             height:100%;
        }
        .head-middle{
                text-align:center;
        }
        .add_middle{
                height:50px;
                float:left;
        }
        .search_middle{
                height:50px;
                float:right;
        }
    </style>
  </head>
  <body>
    <div class="head">
        <h1>学生管理系统</h1>
    </div>
    <div class="middle">{% block content %} {% endblock %}</div>
    <div id="footer">
      {% block footer %} &copy; Copyright 2023 by
      <a href="https://ceshiren.com">测试人社区</a>. {% endblock %}
    </div>
  </body>
</html>
<script type="text/javascript"></script>